by Jeff S. Volek, Ph.D., R.D.
You’ve just worked out. It may have been a cardio workout or a heavy lifting session, but now what? Do you drink a protein shake? Eat a meal? Do nothing? The answer depends on whether you’re trying to lose weight or build muscle. Here are some general guidelines to help you reap the most from your workouts. Start with protein
After a workout your body will be in a catabolic state (breaking down muscle). Whether you’re trying to lose weight or pack on muscle, you need to switch from a catabolic state to an anabolic state (building muscle), which is done by consuming protein.
A good whey protein
supplement is an excellent choice as most are naturally low in carbs and thus, won’t spike insulin and impair fat burning. Whey also has a high prevalence of essential amino acids (the building blocks for muscle), especially the branched-chain amino acids (BCAAs) which are most important for maximizing muscle gain. Whey protein
is digested more quickly than other protein sources resulting in a near immediate rise in muscle protein synthesis.
For example, in trained men who consumed 22 grams of whey, casein or soy isolate following a bout of resistance exercise, muscle protein synthesis was 2 times higher after consuming whey than casein, whereas soy was in-between.1
Studies indicate repeated use of whey during training resulted in improved body composition. In fact, a recent study performed in my lab showed that whey was more effective than an equal amount of soy protein or carbohydrate in boosting muscle mass gains during 9 months of resistance training.2 If your goal is to burn fat
If you’re trying to lose body fat and show more muscle definition, then minimize eating carbs so you don’t stimulate insulin after your workout (as well as throughout the day). Prior work clearly shows that providing even small amounts of carbohydrate after exercise rapidly decreases the breakdown and burning of fat.3
Stimulation of insulin by carbs during recovery has also been shown to diminish the beneficial effects of exercise on insulin sensitivity and other heart disease risk markers.4,5 You might wonder if reducing carbs will compromise muscle gain. The answer appears to be no. When adequate protein is provided after exercise, adding carbs doesn’t increase muscle protein synthesis.6,7 Thus, the primary driver of muscle protein synthesis is not carbs or insulin, but the availability of essential amino acids, especially BCAAs.
On a side note, a fascinating development among high caliber ultra-endurance athletes is that they are abandoning their typical high-carb diet in favor of a high fat, moderate protein, low-carbohydrate diet. These pioneering athletes are not just finishing races; some of them are winning and setting records. My research team has been studying several of these elite low-carb athletes. We documented their extraordinary fat oxidation rates during exercise that are around 50% higher than previously published maximal rates of fat burning. Thus, if you want to lose body fat, keeping carbs and insulin low is the key. A good rule of thumb would be to keep carbs below about 10 grams post-exercise and emphasize slow-absorbing forms that don’t spike insulin. If your goal is to build muscle
If you’re trying to put on mass, then adding carbs
to protein makes sense. The main reason for carbs is to provide additional calories to support weight gain. In order to prevent gaining too much body fat or risking metabolic problems associated with excessive carbs, it would be smart to consume slower absorbing carbs.
You might try adding fat such as olive oil, coconut oil
, flax seed oil
and a small dose of fish oil
to provide EPA and DHA to your post-exercise meal. This will provide additional calories, help even out blood sugar and insulin levels and provide anti-inflammatory nutrients to combat post-exercise stress.
A few other supplements to consider are creatine monohydrate and l-glutamine. Creatine monohydrate
If gaining lean muscle mass and strength is your goal, the research is irrefutable in favor of creatine supplementation. Supplementing with creatine has been shown to increase work capacity during high intensity exercise which translates into better gains in lean body mass and strength over time.
I published the first resistance training study that showed creatine
supplementation increased gains in lean body mass over a decade ago,8 and since then dozens of published studies have confirmed that creatine helps build muscle.
The fastest way to increase muscle creatine
stores is to load with 20 grams per day for 5 days (four 5-gram doses equally spaced through the day) followed by a maintenance period of a single 5 gram daily serving after your workout. L-Glutamine
is an amino acid. In fact, it is the most abundant amino acid in skeletal muscle. Catabolic states, like what high-intensity workouts create, are associated with reductions in muscle glutamine. Several clinical studies indicate that direct infusion of glutamine into the circulation of catabolic patients improves nitrogen balance and recovery.
Immune cells also use a lot of glutamine
as an energy source and one recent study suggests that a glutamine-enriched whey protein enhanced the immune response to exercise.9 More recent work has suggested that glutamine may enhance performance.10 One challenge with oral glutamine is that intestinal cells use it as energy source preventing a large portion of it from entering the circulation. Thus, relatively large supplemental doses are required to elevate blood glutamine levels. Reach your fitness goals
Working out is an investment in your health. In order to get the best return on your workout investment, a good place to start is consuming 20-30 grams of whey protein immediately after exercise. If you prefer a plant-based protein
(soy, rice or pea), consider adding a couple grams of BCAAs to make up for their lower levels of leucine, a key muscle-building amino acid. Creatine
, and maybe glutamine
, can also offer an added boost in muscle mass and performance. It’s also important to use carbs strategically. Restrict them if you want to focus on fat loss and metabolic health, whereas if weight gain is your priority, carbs provide a good source of extra calories.